Analysis of spatial and temporal characteristics of Ca2+ release in permeabilized parotid cells.

Ca2+ waves and oscillations have been observed during stimuli that generate inositol 1,4,5-trisphosphate (IP3) in several exocrine cells, including rat parotid acinar cells. Although a model has been proposed to explain the mechanism of the Ca2+ wave, there exists no direct evidence to prove the model's validity. Analysis with a permeabilized cell system provides direct information about the properties of Ca2+ stores and Ca2+ release channels. We summarize here the experimental techniques that may be used to elucidate the spatial and temporal regulation of Ca2+ in a single permeabilized cell. The future applications of these methods and the possible mechanisms of the Ca2+ wave are also discussed.